Jimmy Lian Ping Mau (JLPM): Our team consists of seven faculty members two of whom are Assistant Professors (Dr. M.C.J Chen and Dr. J.L.P Mau) in the Department of Periodontics at the Chi Mei Medical Center, Tainan, Taiwan (Fig. 1).

JLPM: Our goal was (1) to determine the predictability of the autogenous/BBM/collagen membrane GBR technique and (2) to determine if FDBA can be used to replace the autogenous/BBM bone graft in the GBR technique of early implant placement in the esthetic zone. This was a prospective parallel-designed clinical study, conducted with patients who underwent maxillary anterior single-tooth implant treatment with guided bone regeneration (GBR) at the Chi Mei Medical Center(CMMC) and the University of Texas Health Science Center at San Antonio (UTHSCSA).

JLPM: During my post-graduate dental training in the Department of Periodontics at Chi Mei Medical Center, I was involved in several CBCT research projects into implant bone quality, incisive nerve and mental nerve with my instructor Prof. Tseng (Chair of the ITI Section Taiwan from 2007–2011).

JPML: I met my mentor Prof. Cochran during my Scholarship year in 2010. I was interested in issues related to the esthetic area. After talking to Prof. Cochran, we chose the topic and applied for an ITI research grant for a two-center clinical trial. We completed the research project once I was back in my hospital.

JLPM: As every researcher knows, having research funding is very important and obtaining it is hard and time-consuming these days. The ITI is well organized and easily accessible globally which is of utmost importance in order to be able to provide effective, independent research grant support.

JLPM: This is a two-center clinical trial study. All 48 patients underwent no flap elevation during tooth extraction; and to the greatest extent possible techniques were used that would be less traumatic to the soft and hard tissues. In addition, no alveolar bone preservation was performed. Implant placement was performed 8 weeks after tooth extraction for both the study group and the control group. Implants were placed in the ideal 3D position, the comfort zone. In the control group (Fig. 2), autografts were used to coverthe exposed surface of the implants with one layer of deproteinized bovine bone mineral (DBBM) on top of the autograft, then two layers of non-crosslinked collagen membrane, as the outermost layer. This was followed by suturing. The exposed surface of the implants of the study group (Fig. 3), on the other hand, was covered by freeze-dried bone allograft (FDBA) and topped with two layers of collagen membrane, followed by suturing. The implants used were all bone level implants. The second-stage surgery to connect the healing caps was conducted three months after implant placement, and temporary prostheses were placed two weeks after the wound had healed. Periapical radiographs and cone-beam computed tomographic (CBCT) images were obtained 1-year after implant loading. The distance from mesial and distal implant shoulder radiographic bone-to-implant contact (DIB), and the thickness of the facial bone wall at three different levels: 1, 3, and 5 mm apicalto the implant shoulder were recorded, as was the facial vertical bone wall peak (defined as the distance from the implant platform to the most coronal point of the buccal bone).

The modified plaque index (mPI), modified sulcus bleeding index (mSBI), probing depth (PD), width of keratinized mucosa (KM) of the restoration were recorded after 1 year of loading. Impressions were taken immediately after the crown delivery and after 1 year of loading to produce study casts of the maxilla. These casts were measured directly on the mid-facial height of the implant crown (IC) perpendicular to the incisal plane to identify potential changes in crown height or mucosal recession. All the data collection and measurements were documented by a dentist in each center who did not know which type of treatment the patient had received. For all 48 patients, surgery was conducted by senior, experienced dentists.

JLPM: The modified plaque index (mPI), modified sulcus bleeding index (mSBI) and probing depth (PD) were measured in all 48 patients after 1 year of loading. There were 0.14, 0.24, 3.04 mm and 0.17, 0.31, 3.07 mm between the control and test groups, respectively. There were no significant differences between the control and test groups at 1 year. The width of keratinized gingiva (KM) in the control and test group also showed no difference after 1 year of loading with values of 5.07 mm and 4.42 mm, respectively. According to the measurements obtained from stone models taken 1 year post-loading, there was no buccal mucosal recession in the test group, whereas buccal mucosal recession in the control group was –0.02 mm. In the periapical radiograph, the mean DIB were –0.32 and –0.21 mm in test and control implants, respectively. In the 1-year follow-up analysis, the CBCT analysis of the facial bone wall demonstrated that all implants in the control group and all implants in the test group had a detectable facial bone wall. Examination of the facial bone wall with CBCT below 1 mm, 3 mm, 5 mm were 1.60 mm, 2.20 mm, 2.45 mm in the control group, and 1.60 mm, 1.75 mm, 2.10 mm in the study group. The mean facial bone wall thickness at the 1-, 3- and 5mm levels after 1 year of loading showed no significant difference between the two groups. The data revealed no significant difference in the mean facial vertical bone wall peak after 1 year of loading between the control and study groups with values of 0.80 mm and 0.50 mm coronal to the implant platform, respectively.

JLPM: The findings from this 1-year study reveal that gingival recession was limited, and stable esthetic results were achieved. This 1-year study also demonstrated that (1) consistent contour augmentation can be achieved by multiple clinicians when using autogenous bone and DBBM and a double layer of collagen membrane in type II implant placement, and (2) that excellent results can be achieved at two different centers when using either FDBA or autogenous bone plus DBBM, each combined with a double collagen membrane for augmenting early implant-placed dental restorations.